<!DOCTYPE html>
<meta charset="utf-8">
<meta property="og:image" itemprop="image primaryImageOfPage" content="https://hajimehoshi.github.io/ebiten/images/examples/highdpi.png">
<meta name="description" content="Ebiten example - highdpi">
<link rel="shortcut icon" href="../favicon.png" type="image/png" >
<link rel="icon" href="../favicon.png" type="image/png" >
<title>Ebiten example - highdpi</title>

<link rel="stylesheet" href="../stylesheets/bootstrap.min.css">
<link rel="stylesheet" href="../stylesheets/highlight-github.css">
<link rel="stylesheet" href="../stylesheets/ebiten.css">
<script src="../scripts/googleanalytics.js"></script>

<nav class="navbar"><div class="container">
  <nav class="d-flex flex-row" style="width: 100%;">
    <div class="nav mr-auto"><a class="navbar-brand" href="../"><img src="../images/logo_white.svg" alt="EBITEN"></a></div>
    <ul class="nav">
      <li class="nav-item"><a class="nav-link" href="https://github.com/hajimehoshi/ebiten">GitHub</a></li>
      <li class="nav-item"><a class="nav-link" href="https://godoc.org/github.com/hajimehoshi/ebiten">GoDoc</a></li>
      <li class="nav-item"><a class="nav-link" href="https://github.com/hajimehoshi/ebiten/wiki">Wiki</a>
      <li class="nav-item"><a class="nav-link" href="https://ebiten-playground.github.io/">Playground</a>
    </ul>
  </nav>
</div></nav>

<main><div class="container">

  <h2>Ebiten example - highdpi</h2>
  <iframe src="highdpi.content.html" width="640" height="480"></iframe>
  <div class="card"><pre class="card-body"><code class="language-go">// &#43;build example

package main

import (
        &#34;fmt&#34;
        &#34;image&#34;
        _ &#34;image/jpeg&#34;
        &#34;log&#34;
        &#34;net/http&#34;

        &#34;github.com/hajimehoshi/ebiten&#34;
        &#34;github.com/hajimehoshi/ebiten/ebitenutil&#34;
)

var (
        count          int
        highDPIImage   *ebiten.Image
        highDPIImageCh = make(chan *ebiten.Image)
)

func init() {
        // Licensed under Public Domain
        // https://commons.wikimedia.org/wiki/File:As08-16-2593.jpg
        const url = &#34;https://upload.wikimedia.org/wikipedia/commons/1/1f/As08-16-2593.jpg&#34;

        // Load the image asynchronously.
        go func() {
                res, err := http.Get(url)
                if err != nil {
                        log.Fatal(err)
                }
                defer res.Body.Close()

                img, _, err := image.Decode(res.Body)
                if err != nil {
                        log.Fatal(err)
                }

                eimg, err := ebiten.NewImageFromImage(img, ebiten.FilterDefault)
                if err != nil {
                        log.Fatal(err)
                }

                highDPIImageCh &lt;- eimg
                close(highDPIImageCh)
        }()
}

func update(screen *ebiten.Image) error {
        if highDPIImage == nil {
                // Use select and &#39;default&#39; clause for non-blocking receiving.
                select {
                case img := &lt;-highDPIImageCh:
                        highDPIImage = img
                default:
                }
        }

        if ebiten.IsRunningSlowly() {
                return nil
        }

        if highDPIImage == nil {
                ebitenutil.DebugPrint(screen, &#34;Loading the image...&#34;)
                return nil
        }

        scale := ebiten.DeviceScaleFactor()
        sw, sh := screen.Size()

        w, h := highDPIImage.Size()
        op := &amp;ebiten.DrawImageOptions{}

        // Move the images&#39;s center to the upper left corner.
        op.GeoM.Translate(float64(-w)/2, float64(-h)/2)

        // The image is just too big. Adjust the scale.
        op.GeoM.Scale(0.25, 0.25)

        // Scale the image by the device ratio so that the rendering result can be same
        // on various (diffrent-DPI) environments.
        op.GeoM.Scale(scale, scale)

        // Move the image&#39;s center to the screen&#39;s center.
        op.GeoM.Translate(float64(sw)/2, float64(sh)/2)

        op.Filter = ebiten.FilterLinear
        screen.DrawImage(highDPIImage, op)

        ebitenutil.DebugPrint(screen, fmt.Sprintf(&#34;Device Scale Ratio: %0.2f&#34;, scale))
        return nil
}

func main() {
        const (
                screenWidth  = 640
                screenHeight = 480
        )

        // Pass the invert of scale so that Ebiten&#39;s auto scaling by device scale is disabled.
        s := ebiten.DeviceScaleFactor()
        if err := ebiten.Run(update, int(screenWidth*s), int(screenHeight*s), 1/s, &#34;High DPI (Ebiten Demo)&#34;); err != nil {
                log.Fatal(err)
        }
}
</code></pre></div>

</div></main>

<footer><div class="container">
  <p>© 2013 Hajime Hoshi</p>
  <p>Code is licensed under <a href="https://github.com/hajimehoshi/ebiten/blob/master/LICENSE">the Apache License 2.0</a>.</p>
  <p>The content of this page is licensed under <a href="https://creativecommons.org/licenses/by/4.0/">the Creative Commons Attribution 4.0 License</a>.</p>
</div></footer>

<script src="../scripts/highlight.pack.js"></script>
<script>hljs.initHighlightingOnLoad();</script>
